This device 'listens' to a conversations and then
interjects words and phrases at inappropriate times.

I got this box at a local thrift
store for $1.50 (special, this week only). It has a nice hinged top
and a place to insert a panel with a designed glued to it. Ok, so
I found this frog on the net and dug up the Egyption boarder from somewhere
on my hard drive - viola, Egyption Frog Box!

Now for the talking part.

I found some nifty information at this site by Roman
Blackand decided to experiment
with single-bit sound encoding.

Starting from the ideas at this site, I tried using a single comparator
ic to digitize sound. Very simply put, the incomming audio is sent
to one input of the comparator. The other input connects back to the
PIC chip via a simple r/c network. The PIC reads the output of the
comparator and then outputs a zero or one into the r/c network. This
causes the voltage from the r/c to 'track' the incomming audio signal.

As each bit is output, it is also stored in memory for later playback.
This allows the use of some really, really cheap, (aw heck, I got them for
free) single bit DRAM chip to store the sound.

Here is what it all does: When a loud sound is heard with a pause
before and after it (indicating some short word, phrase, or explitive),
this device records the sound in one of eight memory banks. Then,
at random times, when it detects another slight pause in the converstation,
it plays out one of the recorded sounds.

This unit has now succeeded in really anoying several people.

Further experimentation in single-bit encoding is now in progress here.
If you are doing some work in this area, or are just interested in
using some of this technology, let me know.

Here is the schematic as
it now and the Source and Object
files they stand at present. I have already mounted a small model
airplane servo to raise the lid when it talks, but this has not been added
to the design as yet.